/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 *
 * Remove some unused methods.
 */

/**
 * Remove some unused methods.
 */
package com.tencent.angel.utils;

import java.io.ByteArrayOutputStream;
import java.io.PrintWriter;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.hadoop.conf.Configuration;
import org.slf4j.Logger;

/**
 * General reflection utils
 */
// TODO: 17/6/28 by zmyer
public class ReflectionUtils {
    private static final Class<?>[] EMPTY_ARRAY = new Class[0];

    private static final ConcurrentHashMap CONSTRUCTOR_CACHE = new ConcurrentHashMap();

    private static ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();

    private static long previousLogTime = 0L;

    public static void setConf(Object theObject, Configuration conf) {
        if (conf != null) {
            if ((theObject instanceof Configurable)) {
                ((Configurable) theObject).setConf(conf);
            }
            setJobConf(theObject, conf);
        }
    }

    @SuppressWarnings("unchecked")
    private static void setJobConf(Object theObject, Configuration conf) {
        try {
            Class jobConfClass = conf.getClassByName("org.apache.hadoop.mapred.JobConf");
            Class jobConfigurableClass = conf.getClassByName("org.apache.hadoop.mapred.JobConfigurable");

            if ((jobConfClass.isAssignableFrom(conf.getClass()))
                && (jobConfigurableClass.isAssignableFrom(theObject.getClass()))) {
                Method configureMethod = jobConfigurableClass.getMethod("configure", jobConfClass);
                configureMethod.invoke(theObject, conf);
            }
        } catch (Exception e) {
            throw new RuntimeException("Error in configuring object", e);
        }
    }

    @SuppressWarnings("unchecked")
    public static <T> T newInstance(Class<T> theClass, Configuration conf) {
        Object result;
        try {
            Constructor meth = (Constructor) CONSTRUCTOR_CACHE.get(theClass);
            if (meth == null) {
                meth = theClass.getDeclaredConstructor(EMPTY_ARRAY);
                meth.setAccessible(true);
                CONSTRUCTOR_CACHE.put(theClass, meth);
            }
            result = meth.newInstance(new Object[0]);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        setConf(result, conf);
        return (T) result;
    }

    public static void setContentionTracing(boolean val) {
        threadBean.setThreadContentionMonitoringEnabled(val);
    }

    private static String getTaskName(long id, String name) {
        if (name == null) {
            return Long.toString(id);
        }
        return id + " (" + name + ")";
    }

    private static void printThreadInfo(PrintWriter stream, String title) {
        boolean contention = threadBean.isThreadContentionMonitoringEnabled();
        long[] threadIds = threadBean.getAllThreadIds();
        stream.println("Process Thread Dump: " + title);
        stream.println(threadIds.length + " active threads");
        for (long tid : threadIds) {
            ThreadInfo info = threadBean.getThreadInfo(tid, 20);
            if (info == null) {
                stream.println("  Inactive");
            } else {
                stream.println("Thread " + getTaskName(info.getThreadId(), info.getThreadName()) + ":");

                Thread.State state = info.getThreadState();
                stream.println("  State: " + state);
                stream.println("  Blocked count: " + info.getBlockedCount());
                stream.println("  Waited count: " + info.getWaitedCount());
                if (contention) {
                    stream.println("  Blocked time: " + info.getBlockedTime());
                    stream.println("  Waited time: " + info.getWaitedTime());
                }
                if (state == Thread.State.WAITING) {
                    stream.println("  Waiting on " + info.getLockName());
                } else if (state == Thread.State.BLOCKED) {
                    stream.println("  Blocked on " + info.getLockName());
                    stream.println("  Blocked by "
                        + getTaskName(info.getLockOwnerId(), info.getLockOwnerName()));
                }

                stream.println("  Stack:");
                for (StackTraceElement frame : info.getStackTrace())
                    stream.println("    " + frame.toString());
            }
        }
        stream.flush();
    }

    public static void logThreadInfo(Logger log, String title, long minInterval) {
        boolean dumpStack = false;
        if (log.isInfoEnabled()) {
            synchronized (ReflectionUtils.class) {
                long now = System.currentTimeMillis();
                if (now - previousLogTime >= minInterval * 1000L) {
                    previousLogTime = now;
                    dumpStack = true;
                }
            }
            if (dumpStack) {
                ByteArrayOutputStream buffer = new ByteArrayOutputStream();
                printThreadInfo(new PrintWriter(buffer), title);
                log.info(buffer.toString());
            }
        }
    }

    @SuppressWarnings("unchecked")
    public static <T> Class<T> getClass(T o) {
        return (Class<T>) o.getClass();
    }

    static void clearCache() {
        CONSTRUCTOR_CACHE.clear();
    }

    static int getCacheSize() {
        return CONSTRUCTOR_CACHE.size();
    }
}
